骨髓间充质干细胞移植对树脂毒素介导的小鼠神经病理痛镇痛作用及其机制

The analgesic effect of Bone Mesenchymal Stem Cells transplantation in Resiniferatoxin-induced neuropathic pain in mice

摘要:

摘要 目的：探究骨髓间充质干细胞（BMSC）移植在树脂毒素(Resiniferatoxin, RTX)介导的神经病理痛小鼠的镇痛作用及其机制。方法：36只C57BL/6小鼠随机均分为3组，1. 对照组：小鼠腹腔注射溶剂；2. RTX组：腹腔注射树脂毒素建立RTX神经痛模型；3. BMSC组：骨髓间充质干细胞移植组于造模后5天尾静脉输注骨髓间充质干细胞。在RTX注射后1、5、10、15、20、25、30天分别测量各组小鼠机械缩足阈值和热缩足潜伏阈值。在模型建立后30天分别对三组小鼠进行取材，应用蛋白印迹检测MAPK p38表达量的变化，应用免疫荧光技术检测脊髓背角小胶质细胞活化及BMSC归巢情况，同时应用高尔基染色观察三组小鼠脊髓背角树突棘可塑性变化。结果：RTX组小鼠机械痛阈值在第5天开始下降，第10天及以后机械痛阈值与对照组相比，差异均有显著性(P < 0.05)；BMSC组机械痛阈增加，注射后第20天差异有显著性意义(P < 0.05)。RTX处理后脊髓小胶质细胞标记物ICD11b及p38的表达显著高于对照组，RTX组中小胶质细胞与p38双染高度共定位。BMSCs注射后小胶质细胞激活减弱，p38蛋白表达降低。结论：骨髓间充质干细胞移植在RTX介导的神经病理性疼痛模型中可定向迁移至疼痛中枢敏化部位，可通过减轻小胶质细胞活化和p38通路激活发挥镇痛作用。

Abstract:

Abstract Objective To determine the analgesic effects of bone mesenchymal stem cells (BMSCs) transplantation on RTX induced neuropathic pain in mice and their potential mechanism related to microglia activation. Method A neuropathic pain model was induced by a single intraperitoneal injection of resiniferatoxin (RTX) in C57BL/6 mice. 1x106 GFP-labeled BMSCs were transplanted into the model mice through caudal vein injection, their analgesic potential was evaluated using behavioral tests. The activated microglial marker CD11b and p38 MAPK in the spinal cord were assessed by immunofluorescence and western blot. The dendritic spine profile changes and BMSCs tracings were also determined. Result Pain behavior induced by RTX showed significant hypersensitivity to nociceptive stimuli and lasted for 30 days with activation of microglia compared with control groups, the mechanical allodynia was significantly alleviated after grafts of BMSCs. Meanwhile, p38 MAPK protein level in the spinal cord were also significantly inhibited. RTX mice treated with BMSCs displayed positive immunofluorescence staining for GFP from BMSCs in the dorsal horn. Conclusions Systemic transplantation of BMSCs produce analgesic effect by reducing microglial activation and p38 MAPK level in RTX treated mice.